The naked mole-rat exhibits an unusual cardiac myofilament protein profile providing new insights into heart function of this naturally subterranean rodent Journal Article


Authors: Grimes, K. M.; Barefield, D. Y.; Kumar, M; McNamara, J. W.; Weintraub, S. T.; de Tombe, P. P.; Sadayappan, S; Buffenstein, R.
Article Title: The naked mole-rat exhibits an unusual cardiac myofilament protein profile providing new insights into heart function of this naturally subterranean rodent
Abstract: The long-lived, hypoxic-tolerant naked mole-rat well-maintains cardiac function over its three-decade-long lifespan and exhibits many cardiac features atypical of similar-sized laboratory rodents. For example, they exhibit low heart rates and resting cardiac contractility, yet have a large cardiac reserve. These traits are considered ecophysiological adaptations to their dank subterranean atmosphere of low oxygen and high carbon dioxide levels and may also contribute to negligible declines in cardiac function during aging. We asked if naked mole-rats had a different myofilament protein signature to that of similar-sized mice that commonly show both high heart rates and high basal cardiac contractility. Adult mouse ventricles predominantly expressed alpha-myosin heavy chain (97.9 +/- 0.4%). In contrast, and more in keeping with humans, beta myosin heavy chain was the dominant isoform (79.0 +/- 2.0%) in naked mole-rat ventricles. Naked mole-rat ventricles diverged from those of both humans and mice, as they expressed both cardiac and slow skeletal isoforms of troponin I. This myofilament protein profile is more commonly observed in mice in utero and during cardiomyopathies. There were no species differences in phosphorylation of cardiac myosin binding protein-C or troponin I. Phosphorylation of both ventricular myosin light chain 2 and cardiac troponin T in naked mole-rats was approximately half that observed in mice. Myofilament function was also compared between the two species using permeabilized cardiomyocytes. Together, these data suggest a cardiac myofilament protein signature that may contribute to the naked mole-rat#39;s suite of adaptations to its natural subterranean habitat.
Journal Title: Pflugers Archiv : European journal of physiology
Volume: 469
Issue: 12
ISSN: 1432-2013; 0031-6768
Publisher: Unknown  
Journal Place: Germany
Date Published: 2017
Start Page: 1603
End Page: 1613
Language: eng
DOI/URL:
Notes: LR: 20180331; GR: T32 AG021890/AG/NIA NIH HHS/United States; GR: R01HL105826/National Heart, Lung, and Blood Institute/United States; GR: P01 HL062426/HL/NHLBI NIH HHS/United States; GR: K02HL114749/National Heart, Lung, and Blood Institute/United States; GR: 11PRE7240022/American Heart Association/United States; GR: K02 HL114749/HL/NHLBI NIH HHS/United States; GR: S10 RR025111/RR/NCRR NIH HHS/United States; GR: T32AG021890/National Institute on Aging/United States; GR: P01HL62426/National Heart, Lung, and Blood Institute/United States; GR: 15GRNT22420022/American Heart Association/United States; GR: A10RR025111/National Center for Research Resources/United States; GR: R01 HL075494/HL/NHLBI NIH HHS/United States; GR: 14GRNT20490025/American Heart Association/United States; GR: R01 HL105826/HL/NHLBI NIH HHS/United States; GR: 12GRNT12030299/American Heart Association/United States; GR: F32 HL131304/HL/NHLBI NIH HHS/United States; GR: R01HL75494/National Heart, Lung, and Blood Institute/United States; JID: 0154720; NIHMS947784; OTO: NOTNLM; PMCR: 2018/12/01 00:00; 2017/03/16 00:00 [received]; 2017/07/23 00:00 [accepted]; 2017/06/27 00:00 [revised]; 2018/12/01 00:00 [pmc-release]; 2017/08/07 06:00 [pubmed]; 2017/08/07 06:00 [medline]; 2017/08/07 06:00 [entrez]; ppublish